New Method Maintains Human Lymph Node Activity Ex Vivo

Researchers at the National University of Singapore’s College of Design and Engineering and the National Cancer Centre Singapore have developed a method that maintains human lymph node tissue alive and functional for up to one week outside the body. This technique provides a new way to study human immune responses without having to rely on animal models or simplified cell cultures.

The method involves embedding thin slices of human lymph node tissue into a hyaluronan-based hydrogel scaffold. This hydrogel simulates the tissue’s natural environment and significantly reduces cell loss, allowing the preserved lymph node slices to retain their structure and size. Eliza Fong, senior author of the paper published in Trends in Biotechnology, noted that this approach supports real-time observation of immune cell behaviors, maintaining the tissue’s original architecture and functions.

Traditional lab methods struggle to sustain lymph node tissue for more than a day or two before it loses viability and structure. In contrast, the hydrogel scaffold developed by the team keeps the tissue alive and actively functioning for several days. The tissue responds to exposures, such as cancer cells or a COVID-19 mRNA vaccine, by releasing signaling molecules, activating immune cells, and sometimes even producing antibodies. Notably, one sample produced an immune response even before vaccination, likely indicating previous infection or vaccination in the donor, and demonstrating the platform’s ability to reflect an individual’s immune history.

At present, the hydrogel platform maintains tissue function for about one week, and the team plans to extend this time and incorporate features like lymph flow. The researchers envision that the system could be adapted for fast, human-relevant screening of cancer vaccines, infectious disease vaccines, and immunotherapies, potentially offering an alternative to traditional preclinical testing. 

“Our ultimate goal is to build more predictive models of the human immune system,” said Asst Prof Fong. “This is a significant step in that direction, and one that brings us closer to more effective, personalized ways of treating disease.”